State Key Laboratory for Geomechanics and Deep Underground
Engineering, School of Mechanics and Civil Engineering, China University
of Mining and Technology, Xuzhou 221116, PR China;
*To whom correspondence should be addressed.
Email: yangsqi@hotmail.com
Telephone number: +86-516-83995856
Fax: +86-516-83995678
Address: State Key Laboratory for Geomechanics and Deep Underground
Engineering, China University of
Mining and Technology, Xuzhou 221116, China.
Abstract: The failure behavior of thermal treated granite under
triaxial tiered cyclic loading-unloading compression has a significant
effect on the safe and stable operation of HLW disposal repository.
Therefore, the stress-strain curves, elastic modulus, Poisson’s ratio,
plastic strain, dissipated energy and failure characteristic of the
thermal treated granite specimens under triaxial compression were
analyzed by experiment and numerical simulation. The results indicate
that the elastic, Poisson’s ratio, axial plastic strain, dissipated
energy and accumulative AE counts slightly increase with cyclic loading
at initial loading and elastic deformation stage when T = 25 and
300°C, which means that less damage was induced by cyclic loading.
However, damage occurred once cyclic loading was applied when T =
600°C. Radial strain even showed compressive characteristic in the
initial stage, which indicates that grains adjustment occurred under
triaxial cyclic loading-unloading compression. And, the compressive
characteristic is more obvious with the increase of temperature or the
decrease of confining pressure. The failure modes under triaxial cyclic
loading are more complicated than that under triaxial monotonic loading,
which make the shear plane rougher. Therefore, the residual strength is
higher than that under monotonic loading. When T = 600°C,
micro-crack continuously increases under uniaxial unloading and loading
process, which result in a decrease of the peak strength under cyclic
loading compared with that under monotonic loading.
Key words: Granite; high temperature; cyclic loading-unloading,
dissipated energy, GBM